Sewing machine feeding mechanism



March 16, 1954 A. N. HALE SEWING MACHINE FEEDING MECHANISM 3 Sheets-Sheet 1 Filed July 28, 1952 mb T Q a I E i Hm ms n MN m." MN 3 Wm MM. 3 III, a. aPQ U 1 1 o y rhljl Q a N D INVENTOH W cyqrtkur JIZJJwZe ATTORNEY 1954 A. N. HALE 2,672,112

SEWING MACHINE FEEDING MECHANISM 3 Sheets-$heet 2 IN VEN TOR ogrtkwr JV' Jiwle J m y E 4 6 m m m n w m w Whni ll m 0 .1--- r 1 WWW I. THE 9 1 un RI, a 1 1 m T I i/ m :0: I 9 w mg w w 1 m n w w 1 w w &

March 16,

Filed July 28, 1952 WITNESS March 16, 1954 A. N. HALE SEWING MACHINE FEEDING MECHANISM 5 Sheets-Sheet 3 Filed July 28, 1952 IN VE'N TOR oqrthu/r JV Hale BY ATTORNEY Patented Mar. 16, 1954 SEWING MACHINE FEEDING MECHANISM Arthur N; Hale, Park Ridge, 111., assignor to The Singer Manufacturing Company, Elizabeth,

N. J., a: corporation of New Jersey Application J uly 28,1952, Serial No. 301,271 Claims. (Cl. 112-210) This invention relates to sewing machines and more'particularly'to an improved feeding mechanism for advancing the work past the stitchforming' devices.

It is the primary object of the invention to provide a feeding mechanism which is designed as a unit capable of being put together into a subassembly and applied to the machine in a simple and efficient manner.

A further object of the invention is to provide a feeding mechanism in which the various parts thereof can be readily assembled and maintained in operating condition on the machine to which it is applied by means of two set screws.

A still further object of the invention is to provide a feeding mechanism capable of operating at high speed for sustained periods of time with the need of only infrequent lubrication by virtue of the use of oil impregnated sintered metal bushings at the various bearing points.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices; combinations and arrangements of parts hereinafterset forth and illustrated in the accompanying drawings of a preferred embodimerit of the invention, from which the several features of' the invention and the advantages attained thereby'will bereadil'y understood by those skilled in the art.

Referring to the drawings:

Fig. I is a vertical sectional view taken longitu'dinally of the frame of a sewing machine embodying the invention.

Fig. 2'is an enlarged top plan view of the lower four-motion feeding mechanism, with a portion of the feed-length adjusting means in section.

Fig. 3 is a left end elevation with the faceplate removed from the head, and the clothpla'te, drip-pan and one of the resilient mountings in section.

Fig. 4' is a vertical sectional view taken substantially along the line 4--4, Fig. 2, showing thetwo-part feed advance pitman together with its controlling anchor-link;

Fig. 5 is a disassembled perspective view of the feeding mechanism with the feed-advance and feed-lift eccentrics'in section.

The following detailed description has to do with the-construction of the machine as it relates to the presser mechanism, and for a more complete description of the entire machine reference may be had to my copending application Serial No. 226,082, filed May 12, 1951, of which this application is a division.

Referring more in detail to the drawings; the

machine illustrated has a hollow machine-frame which is preferably cast in one piece and comprises a bed to from one end of which rises a standard ll of an overhanging bracket-arm l2 terminating in a head [3.

The bed is transversely formed with depending end-walls M and [5 providing bearing supports for the opposite end of a mainor bed-- shaft indicated generally as Hi. Intermediate the end-walls l4 and I5 is 9. depending transverse partition ll providing a third bearing for the bed-shaft I6. Spanning the space between the end-wall l4 and the depending partition I!- is a horizontal wall I8 afiording the top of a lubrication compartment l9 closed at its bottom by a removable plate 20. The lubrication compartment I9 is in communication with the hollow 2| of the standard I l, whereby the oilladen atmosphere created in the compartment is may lubricate the operating connections in the bed and standard. Adjacent the right hand end of the bracket-arm 12 there is provided a parti tion 22 separating the hollow of the bracket-arm I2- from the hollow of the standard it and sup-- porting a rear bearing (not shown) for an arm shaft 24. A front bearing 25 for the arm-shaft 24 is mounted in a partial partition 26 formed within the bracket-arm [2 at the point where it merges intothe head I 3 of the machine; A sheetmetal face-plate 21 closes the head' I3 against ingress of dirt and lint and confines anyspent lubricant within the head. To facilitate assembly of the mechanism within the bracket-arm 12 an accessopening 28 is formed in the upper end of the standard and a detachable coverplate 29 is provided toclose said access opening.

Mounted on the bed i0 30 to which is secured a throat-plate 3|. The

entire machine is preferably yieldingly supported on four resilient cushions 32 housed at their upper ends in aperture pads 33' cast integral with the machine-bed l0. Each of the resilient cushions 32 is bored, as at 34, to receive a locating sleeve 35' brazed or otherwise secured to a sheet-metal box-like drip-pan 36. Each of the locating sleeves 35 has a wood-screw 3'! projecting through it to secure the drip-pan to a conventional' table structure 38. It will be appreciated that the locating sleeves 35 position the machine within the drip-pan 36' which is attached to the table-top 38, and that the machine can be readily removed from the drip-pan by simply lifting the machine and the resilient cushions 32 off the locating sleeves 35.

The main-shaft, which is journaled for rotais suitable cloth-plate a feed-advance eccentric i l and a feed-lift eccentric $5.

Carried by the front end of the shaft-section 39 is a conventional form of wing-type looper d6. Brazed or otherwise secured on the reduced rear end portion of the shaft-section St is a counterbalanced disk-shaped crank-cheek t? forming one component of the articulated crank; the crank-cheek being formed in its end face with a radially extending notch 48 and having its periphery 39 cut eccentrically of the axis of retation of the shaft-section 39, thereby to provide an eccentric for actuating a thread-nipper 5t.

Projecting into the radially extending notch 58 in the crank-cheek il is the reduced outer end of a crank-pin 5i brazed or otherwise secured in a second counterbalanced disk-like crankcheek 52 suitably fastened on the rear shaftsection it. As will be seen in Fig. l, the rear shaft-section it? is journaled in ball-bearings 53 and 55 mounted in spaced relation in a sleeve 55 adapted to be replaceably mounted in a shaft assembly aperture 56 formed in the wall l5 of the -ted. Mounted on the exposed end of the rear shaft-section is a combination hand-wheel and belt-pulley 57. For assembly purposes, the aperture 56 is sized to exceed slightly the diameter of the crank-cheek 52 so that the crank-cheek 52 with its crank-pin 5i, shaft iv], ball-bearings 53 and M, sleeve 55 and hand-wheel 51 can be assembled as a unit outside the machine and inserted through the aperture 55. A set-screw 5t locks the unit in place and a conventional resilient ring-gasket 59 prevents escape of the oil in the lubrication compartment l9-2l outwardly along the surface of the aperture 56.

Cooperating with thawing-type looper it in the formation of single thread chain-stitches is a thread-carrying needle 6%) carried in the lower end of an endwise reciprocatory needle-bar Bl journaled in bearing-bushings 62 and 63 fixed in the machine head it. Clamped on the needlebar Si is a stud t l embraced by the lower end of a needle-bar actuating link 65 which is connected at its upper end to a rock-arm 66 clamped on the arm-shaft 2%. Booking movements are imparted to the arm-shaft 24 by means of a rock-arm 5? preferably pinned or otherwise fastened on the standard end of the arm-shaft 2%; the rock-arm 51 having connected to its free end the upper end of a driving link 68 embracing at its lower end the crank-pin 5! on the rotary bedshaft It.

The presser mechanism, which forms the subject of a divisional application Serial No. 301,272, filed July 28, 1952, in its preferred form, comprises a suitable presser-foot 89 carried on the lower end of a vertically disposed presser-bar it endwise slidably mounted in the head it. Surrounding the upper portion of the presser-bar it is a coil-spring ii which biases the presser-foot 69 into engagement with the work by reacting at its upper end against a cap-screw i2 adjustably threaded in the machine-head it and centrally bored to provide the upper bearing for the presser-bar. At its lower end the coil-spring ll engages a presser-bar guiding and lifting bracket 13 clamped by set screw 14 in selected position on the presser-bar it. As shown in Fig. 3, the bracket is guides or, in other words, prevents the presser-bar Hi from turning in its bearings by being formed with a guide-lug it which rides in-a guideway I6 milled in the machine head l3. Projecting reawardly from the bracket [3 is a lifting extension I! disposed vertically above the usual pivotally mounted hand-lifting cam-lever l8. Manual raising of the hand-lifting cam-1ever 18 will cause it to engage the lifting extension ii and thereby raise the presser-foot 69 against the action of the coil-spring H. Lowering of the cam-lever 28 will permit the spring H to return the presser-foot 69 to its lowered workengaging position.

Means is provided for raising the presser-foot 69 by knee-shift or foot-treadle. This means comprises a lifting rock-arm 19 secured, as by brazing, to one end of a presser-lifting rockshaft Bil located rearwardly of the bracket-arm l2 and journaled in spaced bearings (not shown) provided in the bracket-arm. The free end of the lifting rock-arm i9 is oifset or bent at right angles, as at (Fig. 7), to extend into a vertical open-bottom slot 82 formed in the lifting extension TZ. Oscillation of the lifting rock-arm it will cause its offset end 8! to contact the lifting extension H and thus elevate the presserfoot 69. The slot 32 is open at its bottom to permit the hand-lifting lever 18 to be manually raised to elevate the presser-foot without causing movement of the lifting-rock-arm E9. The presser-lifting rock-shaft 86 has secured on it a rearwardly extending actuating lever 83 suitably connected to a knee-shift or foot treadle not shown. A spring 84 acting between the lever 83 and the bracket-arm normally elevates the lever 83 and maintains the lifting rock-arm 19 in engagement with a stop-pin 85 (Fig. 3).

To provide for advancing the work past the stitching devices, the present machine is equipped with a lower four-motion feeding mechanism preferably designed as a unit and capable of being put together as a sub-assembly and applied to the machine in a simple and efficient manner. To that end, the present feeding mechanism includes a feed-dog 86 clamped by a screw 81 for limited vertical adjustment on a feed-bar 88 carrying at its widened rear end a pivot rod 89 of which the opposite ends are journaled in the upstanding limbs 90 of a feed-rocker 9|. The feed-rocker 9! is journaled for oscillatory movements on a fulcrum-stud 92 fixed by a set screw 93 in the machine bed I0.

Lifting movements are imparted to the feeddog 86 by the feed-lift eccentric 55 preferably integral with the exposed end of the mainor bed-shaft [6. The feed-lift eccentric is embraced by a block 94 having flanged opposite faces engaged by the bifurcated end 95 of the feed-bar 88. Rotation of the bed-shaft it will impart to the feed-bar 88 and consequently the feed-dog 86, oscillatory vertical movements about the longitudinal axis of the pivot-rod 138, the oscillations being such as to raise and lower the feeddog 86 into and out of engagement with the material through the usual feed-dog slots in the throat-plate 3!.

The feed-advance and -return movements of the feed-dog as are derived from the feecLadvance eccentric 44 also preferably formed integral with the bed-shaft l6. As will be clearlv seen in Fig.

5. the feed-advance eccentric 44 is embraced by one end of a short pitman 96 connected at its opposite end to a knuckle-pin 9'1 of a pair of toggle-links 98 and 99. The upper end of the toggle-link 98 is connected to a pin I99 fixed in the feed-bar 98 near its rear end. The lower end of the toggle-link 99 is freely journaled on a set pivot or fulcrum-pin I9I fixed in the lower end of an anchor arm 12 supported at its upper end on a rod 593 journaled in alined bearing holes provided in the end-wall I and the partition I7, the rod I 93 providing a fixed pivot about which the anchor-arm I92 is manually turned. From the above description, it will be understood that rotation of the feed-advance eccentric will result in a substantially endwise movement of the upper end of the toggle-link 952; this movement of the toggle-link being transmitted by the pin I99 to the feed-bar 89. Proper relative timing between the feed-lift eccentric 45 and the feedadvance eccentric 44 effects a four-motion travel of the feed-dog 86.

It will be appreciated that the knuckle joint of the toggle-links 93 and 99 is constrained to move in an arc struck about the axis of the fulcrumpin lol, and that by manually swinging the fulcrum-pin I9I about the axis of the anchor-arm supporting rod I93 the horizontal component of the resultant motion of knuckle-pin "9'8 can be changed. This results in a change in the stitchlength. To effect a shift in the position of the fulcrum-pin i9I, means is provided beneath the cloth-plate 39 which can be operated in a manner such that its position of adjustment can be seen through a cut-out I94 (Fig. 3) in the cloth-plate. This means comprises a thin sheet-metal link I95 (Fig. 5) apertured, as at I96, to embrace the slightly extended end or projection I97 of the fulcrum-pin I 9|. At its front end the sheetmetal link I95 is apertured, as at 597', to receive a cylindrical lug I99 extending outwardly from the end-face of a thumb-disk H99 which is supported for turning movement on a stud II9 threaded into the end-wall it. To facilitate the manual turning of the thumb-disk I99 its periphery is flanged and knurled, as at III. Suitable numerals scribed on the periphery of the thumb-disk I99 aid in adjusting the feed to the desired stitch-length. To provide for locking the thumb-disk I99 in selected position, the stud H9 is fitted with a hand-lever M2 by which the stud can be conveniently tightened to clamp the thumb-disk I99 against accidental turning it being understood that the portion of the stud I I9 on which the thumbdisk I09 turns is slightly shorter than the thickness of the thumb-disk I 99 so that tightening of the stud by the hand-lever II2 will effectively lock the thumb-disk against the machine-bed end-wall I5. The hand-lever H2 is adjustably fastened to the stud M9 by a capscrew II3 which secures the hand-lever against the serrated end-face H4 of the stud III]. This permits adjustment of the hand-lever H2 relative to the stud II9. It will be observed in Figs. 1 and 2 that the feeding mechanism in its entirety is located outside the lubrication compartment I9 and, in order to minimize the need for repeated hand oiling of the bearings in the feeding mechanism, bushings H5 (Fig. 5) preferably comprising oil impregnated sintered metal are used wherever possible. Also, the bearing block 94 is preferably made of the same material as the bushings.

Contributing to the simplification of the feeding mechanism is the manner in which the stitchlength adjusting link I95 is maintained operatively connected tothe extended end I97 .of the fulcrum pin ml and the projection I98 on the thumb-disk I99. As will be seen in Figs. 2 and '5, the thumb-disk is provided with a hub H9 and the anchor-arm I92 is milled to provide a finished face I H, the depth of the face Ill and the thickness of the hub II 9 being slightly greater than the thickness of the link I95. When assembled in the machine, the stitch-length adjusting link I 95 is confined at one end between the thumbdisk I99 and the machined outer face IIB of the machine-bed end-wall I5, and at its other end between the anchor-arm I92 and the outer face H8 of the machine-bed end-wall I5. Thus, it will be understood that the means for assembling the thumb-disk m9 and the anchor-arm I92 to the machine-bed also functions to retain the stitch-length adjusting link in its proper operative position. It will be appreciated also that the entire feeding mechanism is adapted to be attached to the machine by the fulcrum-stud 92. This permits the feeding mechanism to be manufactured as a unit or sub-assembly and then readily added to the machine during the final assembly thereof.

Having thus set forth the nature of the invention, what I claim herein is:

l. A sewing machine having a frame including a bed, an actuating shaft journaled in said bed, feed-advance and feed-lift eccentrics mounted on said shaft, a feed-rocker pivotally supported at one side of said actuating shaft, a feed-bar connected at one end to said feedrccker and at its other end to said feed-lift eccentric, a feed-dog carried by said feed-bar, a pair of interconnected toggle-links of which one is connected at its extremity to said feed-bar between said feed-lift eccentric and said feedrocker, an anchor-arm swingable about a fixed pivot and providing at its extremity a set pivot on which the extremity of the second of said toggle links is journaled, a pitman connected at one end to said feed-advance eccentric and at its other end to the knuckle joint of said toggle-links, and means for adjusting the anchorarm about its fixed pivot thereby to shift the set pivot and regulate the feed-advance stroke imparted to said feed-dog.

2. A sewing machine having a frame including a bed, an actuating shaft journaled in said bed, feed-advance and feed-lift eccentrics mounted on said shaft, a feed-rocker pivotally supported at one side of said actuating shaft, a feed-bar connected at one end to said feedrocker and at its other end to said feed-lift eccentric, a feed-dog carried by said feed-bar, a pair of interconnected toggle-links located at the same side of said actuating shaft as is said feedrocker and having one of its links connected at its extremity to said feed-bar between said feedlift eccentric and said feed-rocker, an anchorarm swingable about a fixed pivot and providing at its extremity a set pivot on which the extremity of the second of said toggle links is journaled, a pitman connected at one end to said feed-advance eccentric and at its other end to the knuckle joint of said toggle-links, a manually controlled stitch-length regulating member mounted on said bed and located on the side of said actuating shaft remote from said feed-rocker, and operative connections between said stitch-length regulating member and anchor-arm.

3. A sewing machine having a frame including a bed provided with a flat surface, an actuating shaft journaled in said bed, feed-advance and feed-lift eccentrics mounted on said shaft, a feed-bar, a feed-dog carried thereby, feed-lift means operatively connecting said feed-ba to said feed-lift eccentric, feed-advance and -return means connecting said feed-advance eccentric to said feed-bar, and manually controlled means for regulating the length of stitch including a shiftable anchor-arm disposed adjacent to and swingable about an axis normal to said flat surface, a projection extending from said anchor-arm toward said flat surface, a movable thumb piece, and a link connecting said thumb-piece to said projection on said shiftable anchor-arm, said link being disposed between said anchor-arm and said flat surface and being of slightly less thickness than the distance said anchor-arm is spaced from said flat surface whereby said link is retained on said projection.

4. A sewing machine having a frame including a bed provided with a fiat surface, an actuating shaft journaled in said bed, feed-advance and feed-lift eccentrics mounted on said shaft, a feed-bar, a feed-dog carried thereby, feed-lift means operatively connecting said feed-ba to said feed-lift eccentric, feed-advance and -return means connecting said feed-advance eccentric to said feed-bar, and manually controlled means for regulating the length of feed advance movement including a shiftable anchorarm disposed adjacent to and swingable about an axis normal to said flat surface, a projection extending from said anchor-arm toward said a flat surface, comprising,

fiat surface, a thumb-piece freely journaled on said bed and. having a face disposed adjacent to said flat surface, a lug projecting from the face of said thumb-piece toward said fiat surface, and a flat link connection between the projection on said anchor-arm and the lug on said thumb-piece, said flat link having a thickness less than the distance said thumb-piece is spaced from said flat surface whereby said link is retained in its normal operating position on said lug and projection.

5. A feeding mechanism for a sewing machine having a frame including a bed provided with a feed-dog, a feedbar carrying said feed-dog, feed-lift and feedadvance and -return mechanisms operatively connected to said feed-bar, said feed-advance and -return mechanism including a pair of interconnected toggle links, a pivotally supported anchor-arm operatively connected to said toggle links and adjustable for effecting a change in the feed-advance stroke imparted to said feeddog, and manually controlled means for adjusting said anchor-arm including a disk journaled on said bed and having a knurled periphery, means connecting said disk to said anchor-arm, and a locking device for preventing accidental turning of said disk.

ARTHUR N. HALE.

Name Date Merrow Dec. 15, 1925 Number 

